WO2013053139A1

WO2013053139A1 - Led backlight module and liquid crystal display device

Info

Publication number: WO2013053139A1
Application number: PCT/CN2011/080889
Authority: WO
Inventors: 余亚军
Original assignee: 深圳市华星光电技术有限公司
Priority date: 2011-10-12
Filing date: 2011-10-18
Publication date: 2013-04-18
Also published as: CN102322601A; US8523422B2; US20130094241A1

Abstract

An LED backlight module and a liquid crystal display device. The LED backlight module comprises a light source fixing device (2) for fixing an LED (32) light bar and a light guide plate (4) disposed opposite the LED (32) light bar, the light source fixing device (2) and the light guide plate (4) being fixedly connected. The LED backlight module further comprises a back plate (1). The light source fixing device (2) is movably mounted on the back plate (1). The back plate (1) is provided with an accommodating groove (12) for mounting the light source fixing device (2). A side of the accommodating groove (12) away from the LED (32) of the light source fixing device (2) is provided with a buffer material (6). When the light guide plate (4) expands when heated or contracts when cooled, the light source fixing device (2) can move along the expansion or contraction direction of the light guide plate (4), so as to maintain a light coupling distance between the LED (32) and the light guide plate (4), thereby ensuring a high incidence rate under various temperature conditions.

Description

LED backlight module and liquid crystal display device

[Technical Field]

The present invention relates to the field of display, and more particularly to an LED backlight module and a liquid crystal display device.

【Background technique】

As shown in Fig. 1, in the current LED backlight module, the LED temperature is very high, and the light guide plate is expanded and deformed due to the high temperature due to the high temperature, so that the light coupling between the light incident surface of the light guide plate and the light exit surface of the LED light source is coupled. The distance changes, which seriously affects the light-in efficiency of the LED. In addition, the disappearance of the coupling distance may even force the LED, causing LED dead lights or damage.

[Summary of the Invention]

The technical problem to be solved by the present invention is to provide an LED backlight module and a liquid crystal display device which can ensure high light-input efficiency under different temperature conditions.

The object of the present invention is achieved by the following technical solutions:

An LED backlight module includes a light source fixing device for fixing an LED light bar, a light guide plate opposite to the LED light bar, and the light source fixing device is fixedly connected with the light guide plate.

Preferably, the surface of the light source fixing device that is in contact with the light guide plate is provided with a stepped notch for abutting the light incident surface of the light guide plate. The light source fixing device and the light guide plate can be connected not only by the reflective double-sided tape (or other bonding material), but also a stepped gap is formed at the port position of the light source fixing device and the light guide plate contact surface, the step The notch can control the distance between the light guide plate and the light emitting surface of the LED. The light guide plate is fixed at the stepped notch of the light source fixing device, and the side surface thereof is in contact with the stepped notch side wall of the light source fixing device, and cannot contact the LED with the stepped gap. Therefore, the LED light-emitting surface and the light guide plate can achieve a zero-distance coupling distance without stressing the expansion deformation of the light guide plate to apply pressure to the LED light-emitting surface.

Preferably, the main body of the light source fixing device is fixed to the bottom surface of the light guide plate opposite to the light emitting surface The light source fixing device is provided with an extending portion at a corresponding position of the light emitting surface of the light guide plate; the extending portion of the light source fixing device is fixedly connected to the light emitting surface of the light guide plate. The fixing on both sides is more reliable. In addition, the extension of the light source fixing device can also prevent leakage of light by the LED and improve the light incident rate of the light guide plate.

Preferably, a surface of the light source fixing device that is in contact with the light guide plate is provided with a stepped notch for abutting the light incident surface of the light guide plate. The light source fixing device and the light guide plate can be connected not only by the reflective double-sided tape (or other bonding material), but also a stepped gap is formed at the port position of the light source fixing device and the light guide plate contact surface, the step The notch can control the distance between the light guide plate and the light emitting surface of the LED. The light guide plate is fixed at the stepped notch of the light source fixing device, and the side surface thereof is in contact with the stepped notch side wall of the light source fixing device, and cannot contact the LED with the stepped gap. Therefore, the LED light-emitting surface and the light guide plate can achieve a zero-distance coupling distance without worrying about the expansion and deformation of the light guide plate to apply pressure to the LED light-emitting surface.

Preferably, the light guide plate is fixedly connected to the light source fixing device by a reflective double-sided tape. This is a specific fixing method of the light guide plate and the light source fixing device. The reflective double-sided tape can also reflect the light while fixing the light guide plate and the light source fixing device, and can improve the light incident rate.

Preferably, the LED backlight module further includes a backboard, and the light source fixing device is movably mounted on the backboard.

The back plate is provided with a receiving groove for mounting the light source fixing device, and a buffer material is disposed on a side of the receiving groove opposite to the light source fixing device LED, the buffer material and the light source fixing device The subject is in contact. Since the lamp source fixing device is not fixedly mounted on the back plate, a cushioning material such as rubber or spring having compression elasticity can be selected to resist the lamp source fixing device, thereby preventing the lamp source fixing device and the light guide plate from shaking in the backlight module.

Preferably, the light source fixing device is aluminum extrusion. The metal light source fixing device can effectively fix the LED light bar while taking into consideration the heat dissipation function, and the aluminum extrusion price is moderate, the weight is light, the heat dissipation performance is good, and the cost performance is high.

A liquid crystal display device comprising the above LED backlight module.

In the prior art, the light guide plate is placed on the reflective sheet, and the reflective sheet is placed on the light source fixing device. The light source fixing device is fixed by screws. When the light guide plate is heated and expanded, the coupling distance between the LED light emitting surface of the light source fixing device and the light incident surface of the light guide plate changes, which greatly affects the light entering efficiency of the light guide plate. The disappearance of the coupling distance may even force the LED, causing LED dead lights or damage. In the present invention, the light guide plate and the light source fixing device are fixedly connected. Therefore, when the light guide plate is heated and expanded, the light source fixing device can follow the expansion direction of the light guide plate, and the coupling distance between the LED and the light guide plate remains unchanged. The same is true when the light guide plate is cooled and contracted, and the light source fixing device can follow the contraction direction of the light guide plate, and the coupling distance between the LED and the light guide plate can be kept unchanged. The invention maintains a constant coupling distance between the LED and the light guide plate, and can ensure a high incident rate under various temperature conditions.

[Description of the Drawings]

1 is a schematic structural view of a prior art LED backlight module;

2 is a partial schematic view of an LED backlight module of the present invention;

3 is a schematic view showing a heat sink fin insertion hole of the present invention;

4 is a schematic view of a heat sink fin of the present invention;

5 is a schematic structural view of an LED backlight module without a stepped notch according to an embodiment of the present invention; FIG. 6 is a schematic structural view of an LED backlight module with a stepped notch according to an embodiment of the present invention; FIG. 7 is an LED of Embodiment 2 of the present invention; Schematic diagram of the backlight module;

Among them: 1, the back plate; 11, the fin insertion hole; 12, the receiving groove; 2, the light source fixing device; 21, the heat sink fin; 31, PCB; 32, LED; 4, the light guide plate; 51, reflective double-sided tape; 6, cushioning material.

【detailed description】

The invention will now be further described with reference to the drawings and preferred embodiments.

A liquid crystal display device includes an LED backlight module, the LED backlight module includes a light source fixing device 2 for fixing an LED 32 light bar, and a light guide plate 4 opposite to the LED 32 light bar, fixing the back of the light source fixing device 2 The light source fixing device 2 is fixedly connected to the light guide plate 4, and the light source is solid The fixture 2 is movably mounted on the backing plate 1. The lamp source fixing device is a metal material with better heat dissipation performance such as aluminum extrusion, and can effectively fix the LED light bar while taking into consideration the heat dissipation function, and the aluminum extrusion price is moderate, the weight is light, the heat dissipation performance is good, and the cost performance is high.

The inventive concept is explained below in conjunction with specific embodiments:

Embodiment 1

As shown in FIGS. 1 to 6, the LED 32 light bar includes an LED 32, and a PCB 31 connected to the LED 32, and the PCB 31 is fixed to the light source fixing device 2. The side of the light source fixing device 2 in contact with the back plate 1 is a bottom portion, and a reflection sheet 5 is disposed on a bottom side of the light source fixing device 2, and a light guide plate 4 is disposed on the reflection sheet 5, and one side of the light guide plate 4 is opposite to the LED 32. . The bottom surface of the light guide plate 4 in contact with the reflective sheet 5 partially overlaps the main body of the light source fixing device 2, and the two are fixed together by the reflective double-sided tape 51 or other viscous material. Of course, the light source fixing device 2 and the light guide plate 4 Other fixing methods such as screw fixing and riveting can also be used.

Further, the back plate 1 is provided with a receiving groove 12 for mounting the light source fixing device 2, and a plurality of segments are disposed between the side opposite to the light bar fixing device 2 and the wall of the receiving groove 12 Or a cushion rubber 6 such as a rubber strip or a spring having a compression elasticity. Since the light source fixing device 2 is not fixedly mounted on the back plate 1, the cushioning material 6 such as rubber or spring having compression elasticity is pressed against the light source fixing device 2, so that the light source fixing device 2 and the light guide plate 4 can be prevented from being in the backlight module. Shake inside.

Further, a surface of the light source fixing device 2 that is in contact with the light guide plate 4 is provided with a stepped notch for abutting the light incident surface of the light guide plate 4. Between the lamp source fixing device 2 and the light guide plate 4, not only the reflective double-sided tape 51 (or other bonding material) can be connected, but also a step is formed at the port position of the contact surface between the lamp source fixing device 2 and the light guide plate 4. The stepped notch can control the distance between the light guide plate 4 and the light emitting surface of the LED 32. The light guide plate 4 is fixed at the stepped notch of the light source fixing device 2, and the side surface thereof is in contact with the stepped notch side wall of the light source fixing device 2. Therefore, the stepped notch can not be in contact with the LED 32, so that the light-emitting surface of the LED 32 and the light guide plate 4 can achieve a zero-distance coupling distance without stressing the expansion deformation of the light guide plate 4 to apply pressure to the light-emitting surface of the LED 32.

Embodiment 2

As shown in FIG. 1 to FIG. 4 and FIG. 6 to 7, the main body of the light source fixing device 2 and the light guide plate 4 and The light source fixing device 2 is provided with an extending portion at a corresponding position of the light-emitting surface 4 of the light guide plate; the extending portion of the light source fixing device 2 is fixedly connected to the light-emitting surface of the light guide plate 4. Row connection, of course, the light source fixing device 2 and the light guide plate 4 can also be fixed by screws, riveting or the like. The two sides are more reliable in fixing, and the extension on the light source fixing device 2 is connected with the light emitting surface of the light guide plate 4, so that a relatively sealed space is formed between the light source fixing device 2 and the light guide plate 4, which can be effective. Prevent the light leakage of LED32 and avoid the phenomenon of light leakage.

Further, the back plate 1 is provided with a receiving groove 12 for mounting the light source fixing device 2, and a plurality of segments are disposed between the side opposite to the light bar fixing device 2 and the wall of the receiving groove 12 Or a whole section of rubber strips, springs, etc., which have a certain compressive elasticity. Since the light source fixing device 2 is not fixedly mounted on the back plate 1, the cushioning material 6 such as rubber or spring having compression elasticity is pressed against the light source fixing device 2, so that the light source fixing device 2 and the light guide plate 4 can be prevented from being in the backlight module. Shake inside.

Embodiment 3

As shown in FIG. 1 to 7, the bottom surface of the light source fixing device 2 in contact with the back plate 1 is further provided with heat dissipation fins 21, and the shape of the fins may be a sheet shape or other shapes such as a column shape. Correspondingly, a fin insertion hole 11 is formed in the receiving groove 12 of the back plate 1 corresponding to the heat dissipation fin 21, and the heat dissipation fin 21 passes through the fin insertion hole 11 on the back plate 1, and is exposed on the LED backlight mode. Outside the group.

Further, the fin insertion hole 11 and the heat dissipation fin 21 adopt a clearance fit, and the fin The insertion hole 11 leaves a space for the heat dissipation fins 21 to move in the direction facing the light guide plate 4. Thus, the light source fixing device 2 can follow the direction of thermal expansion or cold contraction of the light guide plate 4 to maintain the spacing between the LED 32 lamp and the light guide plate 4, ensuring a high light incident rate. For the technical solutions for ensuring high light-input efficiency under different temperature conditions, reference may be made to the first embodiment and the second embodiment.

A plurality of heat dissipation fins 21 are formed on the bottom of the light source fixing device 2, and the shape of the heat dissipation fins 21 may be a sheet shape or other shapes such as a column shape. Of course, the heat dissipation fins 21 may also be other in the light source fixing device 2. position. A light source fixing device 2 having a certain depth is formed inside the back plate 1 to accommodate the groove 12, and a hole corresponding to the shape of the heat sink fin 21 of the light source fixing device 2 is cut out in the receiving groove 12 to form a fin insertion hole 11. Further, the fin insertion hole 11 has a certain margin, so that the heat dissipation fins 21 of the lamp source fixing device 2 are passed through the fin insertion holes 11 of the receiving groove 12 of the back plate 1 and face the light guide plate. There is a certain moving space in the direction of 4, so that the heat generated by the LED 32 is directly radiated into the air through the light source fixing device 2, effectively reducing the temperature of the entire backlight module and prolonging the service life of the LED 32.

At the same time, the LED 32 light bar is attached or locked to the light source fixing device 2. In order to ensure the light-increasing efficiency of the LED 32, the light-emitting surface of the LED 32 and the light-incident surface of the light guide plate 4 must be kept at a fixed suitable coupling distance. However, the temperature of the LED 32 is high, and the light guide plate 4 is extremely susceptible to thermal expansion and deformation, resulting in a deviation between the coupling distance and the initially set value. Guided by the fins of the lamp source fixing device 2 and the holes corresponding to the fins in the accommodating groove 12, when the light guide plate 4 is thermally expanded, the light guide plate 4 guides the force generated by the deformation amount to the lamp source fixing device 2, And the light source fixing device 2 is offset back together in the accommodating groove 12, and does not let the light guide plate 4 directly press the surface of the LED 32, thereby accurately maintaining the fixed coupling distance of the light-emitting surface of the light guide plate 4 and the LED 32; When lowered, the light guide plate 4 returns to its original shape, and the light source fixing device 2 returns to the original position along with the light guide plate 4, and still maintains a fixed coupling distance. The coupling distance can even be zero, and there is no need to worry about the LED 32 being crushed. risks of.

In order to avoid the occurrence of light leakage, the present invention reduces the temperature of the entire backlight module and prolongs the service life of the LED 32 by convection of the heat dissipation fins 21 of the light source fixing device 2 and the air to reduce the service life of the LED 32; The stability of the coupling distance between the light-emitting surface and the light-incident surface of the light guide plate 4 is high, and the light-in efficiency is improved; the margin space of the light source fixing device 2 can absorb the thermal expansion of the light guide plate 4 The shape prevents the deformation of the light guide plate 4; the positioning of the cut-free light guide plate 4 can be realized, and the processing cost of the light guide plate 4 can be saved.

The above is a further detailed description of the present invention in conjunction with the specific preferred embodiments. It is not intended that the specific embodiments of the invention are limited to the description. It will be apparent to those skilled in the art that the present invention can be made without departing from the spirit and scope of the invention.

Claims

Rights request

An LED backlight module, comprising: a light source fixing device for fixing an LED light bar, a light guide plate opposite to the LED light bar, wherein the light source fixing device is fixedly connected with the light guide plate.

2. The LED backlight module according to claim 1, wherein the surface of the light source fixing device that is in contact with the light guide plate is provided with a stepped notch for abutting the light incident surface of the light guide plate.

The LED backlight module of claim 1 , wherein the main body of the light source fixing device and the bottom surface of the light guide plate opposite to the light emitting surface are fixedly connected; An extension portion is disposed at a corresponding position of the light-emitting surface of the light plate; and an extension portion of the light source fixing device is fixedly connected to the light-emitting surface of the light guide plate.

The LED backlight module according to claim 3, wherein the surface of the light source fixing device that is in contact with the light guide plate is provided with a stepped notch for abutting the light incident surface of the light guide plate.

The LED backlight module according to claim 1, wherein the light guide plate is fixedly connected to the light source fixing device by a reflective double-sided tape.

6. The LED backlight module of claim 1, wherein the LED backlight module further comprises a backplane, and the light source fixing device is movably mounted on the backplane.

7. The LED backlight module of claim 6, wherein the backplane is provided with a receiving slot for mounting the light source fixing device, and the receiving slot and the light source fixing device LED The opposite side is provided with a cushioning material that is in contact with the body of the light source fixture.

8. The LED backlight module of claim 1, wherein the light source fixing device is aluminum extrusion.

A liquid crystal display device, comprising the LED backlight module of claim 1, wherein the LED backlight module comprises: a light source fixing device for fixing the LED light bar, and a light guide plate opposite to the LED light bar, The light source fixing device is fixedly connected to the light guide plate.

10. A liquid crystal display device according to claim 9, wherein said light source The surface of the fixing device that is in contact with the light guide plate is provided with a stepped notch for abutting the light incident surface of the light guide plate.

The liquid crystal display device according to claim 9, wherein the main body of the light source fixing device is fixedly connected to a bottom surface of the light guide plate opposite to the light emitting surface; and the light source fixing device is disposed on the light guide plate. An extension portion is disposed at a corresponding position of the light-emitting surface; and an extension portion of the light source fixing device is fixedly connected to the light-emitting surface of the light guide plate.

The liquid crystal display device according to claim 11, wherein a surface of the light source fixing device that is in contact with the light guide plate is provided with a stepped notch for abutting the light incident surface of the light guide plate.

13. A liquid crystal display device according to claim 9, wherein the light guide plate is fixedly coupled to the light source fixing device by a reflective double-sided tape.

14. The liquid crystal display device as claimed in claim 9, wherein the LED backlight module further comprises a back plate, and the light source fixing device is movably mounted on the back plate.

The liquid crystal display device according to claim 14, wherein the back plate is provided with a receiving groove for mounting the light source fixing device, and the receiving groove is opposite to the light source fixing device LED. A cushioning material is provided on one side of the back, and the cushioning material is in contact with the body of the light source fixing device.

A liquid crystal display device according to claim 9, wherein said light source fixing means is aluminum extruded.